<div class="ant-menu-item-group-title">
  <ng-container *nzStringTemplateOutlet="nzTitle">{{ nzTitle }}</ng-container>
  <ng-content select="[title]" *ngIf="!nzTitle"></ng-content>
</div>
<ul class="ant-menu-item-group-list">
  <ng-content></ng-content>
</ul>